ISRO launches 1st sun mission as India eyes place in elite orbit

Shubhadeep Choudhury

New Delhi, September 2

After its successful lunar expedition a few days ago, the Indian Space Research Organisation (ISRO) on Saturday launched its first solar observation mission.

The success of the mission will see India join an elite club consisting of NASA, European Space Agency (ESA) and Japan, which have set up observatories in space to study the sun.

Murmu compliments PM on lunar success

PM Narendra Modi on Saturday called on President Droupadi Murmu, who complimented him for the success of India’s Chandrayaan-3 mission, said the President’s office.

Blasting off from the ISRO spaceport at Sriharikota in Andhra Pradesh, a 44.4-m four-stage PSLV XL rocket on Saturday placed the Aditya-L1 satellite — India’s first space-based observatory — in an elliptical low-earth orbit after more than one hour of flight.

“The Aditya-L1 spacecraft has been put into an elliptical orbit of 235×19,500 km,” said S Somanath, chairman, ISRO. Union Minister of State for Science and Technology and Department of Space Jitendra Singh, who witnessed the launch, described it as a “sunshine moment for India”.

For entire humanity

Congratulations to our scientists and engineers at ISRO for the successful launch. Efforts will continue for better understanding of the universe for the welfare of entire humanity. Narendra Modi, PM

After some earth-bound manoeuvres, Aditya-L1 will start its journey toward the L1 point located 15 lakh km away from the earth. The travel time – from the launch to reaching the L1 point – would be around 125 days, Somanath said.

L1 or Lagrange point 1 is a spot between the sun and the earth. According to Biman Nath of Raman Research Institute, Bengaluru, a Lagrange point is a spot where the gravitational forces of two large objects — such as the sun and the earth — work on each other and create a stable position for an object in between. Once Aditya-L1 reaches the L1 point, it would be able to orbit the sun at the same rate as the earth. Space-based solar observatories of the ESA and NASA are also positioned there.

The spacecraft is planned to be placed in a halo orbit around the Lagrange point 1, ISRO said, adding that the satellite placed in the halo orbit around L1 could continuously view the sun even during an eclipse. Aditya-L1 carries seven indigenously developed scientific payloads. The instruments will observe and study the solar corona (the outermost layer), the photosphere (the sun’s surface or the part we see from the earth) and the chromosphere (a thin layer of plasma that lies between the photosphere and the corona).

The data will help scientists understand solar activity, such as winds and flares, and its effect on the earth and near-space weather in real time. Information about solar activities will also help ISRO protect Indian satellites better, say ISRO scientists.

Rover set in sleep mode

• Chandrayaan-3’s rover has moved 100m from lander; both working well
• Rover’s goal has been achieved & it has been set into sleep mode

Lagrange point

• At Lagrange point 1 (L1), the gravitational pull of the sun and the earth will be equal and hence the spacecraft will not gravitate towards any one of these
• L1 distance from earth is approx 1% of the earth-sun distance

Solar observatory

• Once spacecraft reaches L1, it will study the solar corona, photosphere and chromosphere
• Data to help understand solar activity, its effect on earth and near-space weather in real time

Manoeuvre today

• 11.45 pm, Sunday Satellite’s first earth-bound manoeuvre to raise its orbit scheduled
• The spacecraft has already deployed its solar panels and has started generating power